title: Levocetirizine modulates lymphocyte activation in patients with allergic rhinitis.
abstract: Levocetirizine, a second generation non-sedating antihistamine that blocks the H(1) histamine receptor, may exhibit immunoregulatory properties that augment its primary pharmacological mechanism. To investigate this possibility, 13 Kuwaiti seasonal allergic rhinitis (SAR) patients were treated with levocetirizine for four weeks in comparison with a 7-member placebo-treated control group, followed by clinical evaluation and flow cytometric analysis of peripheral venous blood for inflammatory cell and lymphocyte subpopulation profiles. Relative to the controls, levocetirizine-treated patients exhibited an expected reduction in early phase allergic symptoms, including sneezing (P<0.001), nasal itching (P<0.01), nasal congestion, and running nose (P<0.001); reduced percentages of eosinophils (P<0.05); and three subpopulations of activated T lymphocytes: CD4+CD29+, CD4+CD212+, and CD4+CD54+ (P<0.05). Levocetirizine treatment also correlated with a significant increase in the percentage of CD4+CD25+ T cells (P<0.001). The ability of levocetirizine to reduce percentage representation of cell phenotypes known to contribute to inflammatory tissue damage (eosinophils, CD4+CD29+, CD4+CD212+, and CD4+CD54+) and expand percentages of CD4+CD25+, which may include protective immunoregulatory (Treg) cells, indicates that the drug has pharmacological potential beyond the immediate effects of H(1) histamine-receptor inhibition. Although the present data does not define a therapeutic mechanism, the results reported here establish important trends that may be used to guide future mechanistic examination of immunoregulatory capacity of H(1) inhibitors.
authors.affiliation: Department of Medical Laboratory Sciences, Faculty of Allied Health Sciences, Kuwait University, Kuwait. fadia@hsc.edu.kw
authors.forename: Fadia
authors.initials: F
authors.lastname: Mahmoud
authors.forename: Nirmina
authors.initials: N
authors.lastname: Arifhodzic
authors.forename: David
authors.initials: D
authors.lastname: Haines
authors.forename: Ladislav
authors.initials: L
authors.lastname: Novotney
mesh_terms: D000328:Adult; D000893:Anti-Inflammatory Agents / Q000627:therapeutic use*; D017332:Cetirizine / Q000627:therapeutic use*; D004804:Eosinophils / Q000187:drug effects / Q000276:immunology; D005260:Female; D039563:Histamine H1 Antagonists, Non-Sedating / Q000627:therapeutic use*; D006801:Humans; D016130:Immunophenotyping; D008213:Lymphocyte Activation / Q000187:drug effects*; D008297:Male; D011537:Pruritus / Q000276:immunology / Q000517:prevention & control; D006255:Rhinitis, Allergic, Seasonal / Q000188:drug therapy* / Q000276:immunology; D012912:Sneezing / Q000187:drug effects; D016176:T-Lymphocyte Subsets / Q000187:drug effects* / Q000276:immunology; D016896:Treatment Outcome
chemical_list: D000893:Anti-Inflammatory Agents; D039563:Histamine H1 Antagonists, Non-Sedating; C472067:levocetirizine; D017332:Cetirizine